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arXiv · 1901.02580

Crystal structures and the sign reversal Hall resistivity in iron-based superconductors Lix(C3H10N2)0.32FeSe (0.15<x<0.4)

Ruijin Sun·Shifeng Jin·Jun Den·Munan Hao·Linlin Zhao·Xiao Fan·Xiaoning Sun·Jiangang Guo·Lin Gu·Xiaolong Chen
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Abstract

We report the crystal structure, superconductivity and normal state properties of two iron-based materials, Li0.15(C3H10N2)0.32FeSe(P-4) and Lix(C3H10N2)0.32FeSe(P4/nmm, 0.25<x<0.4) with superconducting transition temperature from 40~46K. The determined crystal structures revealed a coupling between Li concentration and the oritation of 1,2-Diaminopropane molecules within the hyper expanded FeSe layers. Further fitting on resistivity in terms of the Lawence-Doniach model suggests the two superconductors belong to the quasi-two dimonsional system. With increasing temperature, a differences in crystal structures and doping levels. First principle calculations revealed the increase in FeSe layer diatance will restruct the Fermi surface and generate a new hole pocket around Gamma point in the Brillouin Zone. Our findings support that the increase in two dimensionalities will leads to a temperature induced Lifshitz transition in electron doped FeSe superconductors.

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Ruijin Sun, Shifeng Jin, Jun Den, Munan Hao, Linlin Zhao, Xiao Fan, Xiaoning Sun, Jiangang Guo, Lin Gu, Xiaolong Chen. 2019-01-09. Crystal structures and the sign reversal Hall resistivity in iron-based superconductors Lix(C3H10N2)0.32FeSe (0.15<x<0.4). https://doi.org/10.1088/1674-1056/28/6/067401

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